Chairs and other types of furniture with legs require some type of termination on the legs to prevent the ends of the legs from becoming embedded in the surface on which they are placed and to allow the chair or piece of furniture to be moved more easily. Typically, furniture legs may be terminated either by finishing the end of the leg to give a smooth surface, by attaching a foot or glide, or by attaching a roller or a wheel to the bottom of the leg. Some furniture legs are solid, such as solid wood, and may be finished so as to give a smooth end, or some type of foot or glide may be attached to the solid leg. Other types of furniture, especially office furniture, have legs formed of hollow metal tubing. These legs are typically terminated by attaching some type of foot or glide to the bottom of the leg.
As shown in FIG. 1, a typical chair 10 will have four legs 12 each terminating in a glide 14. Several attachment approaches have been developed for attaching glides 14 to the bottom of chair legs 12. It is desirable for the attachment interconnecting the glide 14 with the chair leg 12 to securely attach the glide 14 to the chair leg 12 and to resist twisting forces and shearing (side to side) forces. It is also desirable that the attachment be easily assembled onto or into the chair leg 12, and that the attachment be inexpensive and durable.
One type of attachment for attaching a glide to a chair leg is shown in U.S. Pat. No. 5,287,595 to Stevens Jr. This patent shows a combination glide and pintle which is formed as a unitary piece from plastic. The pintle portion is inserted into a chair leg thereby retaining the glide portion to the chair leg. A drawback to this combination device is that the plastic may not provide sufficient strength for some applications. Also, the pintle portion may be unable to develop sufficient grip to securely retain the glide in the chair leg.
Referring now to FIGS. 4 and 5, another prior art attachment approach is shown. In these figures, a glide assembly 16 is attached to a chair leg 20 which is a hollow metal tube with a generally square cross section. The glide assembly 16 includes a glide base 18 which is designed to contact a floor. The glide base 18 is interconnected with the chair leg 20 by an attachment plate 22 and support collar 24. The attachment plate 22 rests against the bottom of the chair leg 20 and the support collar 24 surrounds the attachment plate 22 and the bottom of the chair leg 20. The attachment plate 22 resists upward forces on the glide base 18 so that the glide base 18 is not forced up into the chair leg 20. The support collar 24 grips the outside of the chair leg 20 and resists shearing and twisting forces. The attachment plate 22 is typically made out of metal and the support collar 24 may be made out of metal or plastic. The glide assembly 16 is held into the chair leg 20 by a clip 25 which is typically made from spring steel. A major drawback to the glide assembly 16 shown in FIGS. 4 and 5 is aesthetics. Some purchasers feel that this type of glide assembly is cheap looking because of the visible support collar 24. These purchasers typically request a glide assembly that eliminates the support collar 24. However, the support collar 24 may not be eliminated from the glide assembly 16 shown in FIGS. 4 and 5 because the support collar 24 serves the important purpose of resisting twisting and shear forces. Elimination of the support collar 24 would allow the attachment plate 22 to move and twist thereby hurting the performance of the glide assembly 16.
To overcome the limitations of the glide assembly 16, shown in FIGS. 4 and 5, a collarless glide assembly 26 was developed, as shown in FIGS. 2 and 3. In this variation, the attachment plate 28 is designed with a raised interior portion 30 which acts to help keep the attachment plate 28 centered in the chair leg 32. Like in the previous version, the glide assembly 26 is held in the chair leg 32 by a spring steel clip 34. While this type of glide assembly avoids the need for a support collar, it has proven less than satisfactory when it comes to resisting shearing and twisting forces. The attachment plate 28 with the raised interior portion 30 does not solidly locate the glide assembly 26 into the bottom of the chair leg 32.
There remains a need for a collarless glide assembly that resists shear and twisting forces, is easy to install, durable, and inexpensive.